Vehicle cabs have generally been constructed of sheet metal, and directly fastened through bolts to a steel frame that attached to the vehicle chassis. Fiberglass could be used in constructing the sides and top of the cab to enable more complex shapes to be used at lower costs and to guard against corrosion. However, fiberglass or other plastic cabs are not compatible with the steel frames and flooring, in that large localized loads that can be withstood by steel members could cause cracking of the fiberglass. A truck cab which could employ a plastic housing for its side and top wall, while enabling the use of steel or other metals for the frame and for the flooring to which the cab must be attached, would enable the use of more complex and decorative shapes for the cab at low cost, while obtaining other advantages of plastic such as corrosion resistance, light weight, and minimization of noise.